NOMOS watches in the aqua series are water resistant up to 20 atm / 200 meters. Examples include all models in the Ahoi series, and Club models such as the 740, 741, 742, 743, 775, 776, and 777.
atlantik, or atlantic, is a deep blue color. Like tiefblau, it is close to RAL 5008-5011.
grau, or grey, is a light grey color close to RAL 7038. It is used on watches such as the 124 and 125.
nachtblau, or midnight blue, is a deep blue color that’s close to RAL 5026. It is sued on watches such as the 177, the 1205, and 1110. The Tetra 422 changed from tiefblau to nachtblau in late 2016.
signalblau, or siren blue, is a bright blue color that’s close to RAL 5015. It is used on watches such as the 562, 554, 742, and 777.
signalrot, or siren red, is a bright red color that’s close to RAL 3028. It is used on watches such as the 743 and 563.
tiefblau, or deep blue, is a deep blue color that was used on the first generation Tetra 422. It is close to RAL 5008-5011.